Microwave Packaging

ABSTRACT

A container for heating a food product with microwave energy having a wavelength. The container can include a generally circular centerline having an axis, and a receptacle including a sidewall extending at least partially around a cavity. At least a portion of the cavity can extend along at least a portion of the centerline. The sidewall can include an inner edge and an outer edge each being spaced apart from the axis of the centerline for at least partially retaining the food product in the cavity in proximity to the centerline.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 14/814,638, filed Jul. 31, 2015, which claims the benefit ofU.S. Provisional Patent Application No. 61/999,647, filed on Aug. 1,2014.

INCORPORATION BY REFERENCE

The disclosures of U.S. patent application Ser. No. 14/814,638, whichwas filed on Jul. 31, 2015, and U.S. Provisional Patent Application No.61/999,647, which was filed on Aug. 1, 2014, are hereby incorporated byreference for all purposes as if presented herein in its entirety.

BACKGROUND OF THE DISCLOSURE

The present disclosure relates to blanks, containers, trays, constructs,and various features to facilitate forming a container from a blank.

SUMMARY OF THE DISCLOSURE

In one aspect, the disclosure is generally directed to a container forheating a food product with microwave energy having a wavelength. Thecontainer can comprise a generally circular centerline having an axis,and a receptacle comprising a sidewall extending at least partiallyaround a cavity. At least a portion of the cavity can extend along atleast a portion of the centerline. The sidewall can comprise an inneredge and an outer edge each being spaced apart from the axis of thecenterline for at least partially retaining the food product in thecavity in proximity to the centerline.

In another aspect, the present disclosure is generally directed to amethod of heating a food product. The method can comprise obtaining acontainer comprising a generally circular centerline having an axis, anda receptacle comprising a sidewall extending at least partially around acavity. At least a portion of the cavity can extend along at least aportion of the centerline. The sidewall can comprise an inner edge andan outer edge each being spaced apart from the axis of the centerlinefor at least partially retaining the food product in the cavity inproximity to the centerline. The method further can comprise positioningat least a portion of the food product in the cavity, and exposing thecontainer and the food product to microwave energy having a wavelength.

Those skilled in the art will appreciate the above stated advantages andother advantages and benefits of various additional embodiments readingthe following detailed description of the embodiments with reference tothe below-listed drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

According to common practice, the various features of the drawingsdiscussed below are not necessarily drawn to scale. Dimensions ofvarious features and elements in the drawings may be expanded or reducedto more clearly illustrate the embodiments of the disclosure.

FIG. 1 is a top perspective view of a container according to a firstembodiment of the disclosure.

FIG. 2 is a top plan view of the container of FIG. 1.

FIG. 3 is an elevation view of the container of FIG. 1.

FIG. 4 is a top perspective view of the container of FIG. 1 with aprimary food item and a secondary food item according to the firstembodiment of the disclosure.

FIG. 5 is a top perspective view of the container of FIG. 1 with adifferent primary food item according to the first embodiment of thedisclosure.

FIG. 6 is a top perspective view of a container according to a secondembodiment of the disclosure.

FIG. 7 is a top plan view of the container of FIG. 6.

FIG. 8 is an elevation view of the container of FIG. 6.

FIG. 9 is a top perspective view of a container according to a thirdembodiment of the disclosure.

FIG. 10 is a top perspective view of a support element of the containerof FIG. 9.

FIG. 11 is a top perspective view of a plurality of receptacles of thecontainer of FIG. 9.

Corresponding parts are designated by corresponding reference numbersthroughout the drawings.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present disclosure relates generally to various aspects ofcontainers, constructs, trays, materials, packages, elements, andarticles, and methods of making such containers, constructs, trays,materials, packages, elements, and articles. Although several differentaspects, implementations, and embodiments are disclosed, numerousinterrelationships between, combinations thereof, and modifications ofthe various aspects, implementations, and embodiments are contemplatedhereby. In one illustrated embodiment, the present disclosure relates toa container or tray for holding, heating, and/or cooking food items orvarious other articles. However, in other embodiments, the container ortray can be used to form other non-food containing articles or may beused for refrigerating or other uses.

FIGS. 1-3 illustrate a container 5 with a generally toroid-shapedreceptacle 11 according to a first embodiment of the disclosure. In theillustrated embodiment, the container 5 is a tray or a bowl that iscurved (e.g., circular) along an outer perimeter and along an innerperimeter. The container 5 can be press formed and/or erected from ablank (not shown). It is understood that the blank can be press-formedinto the container 5 by a forming tool (not shown), through a one-stepor multi-step forming process by which the blank is cut from a supplystock and press-formed into the container 5 by any suitable forming toolassembly. Alternatively, the container 5 could be erected from one ormore blanks (not shown) such as by folding and/or gluing differentaspects of the blank(s) to form the container. Also, the container 5could be alternatively and/or could be alternatively formed withoutdeparting from the scope of this disclosure.

The container 5 can be formed from a single layer, such as, but notlimited to, paperboard, cardboard, paper, or a polymeric sheet.Alternatively, the carton 5 can be formed from more than one layer(e.g., a laminate). In accordance with the exemplary embodiments of thepresent disclosure, a laminate can include a lamination layer mounted ona substrate or base layer (e.g., a polymer lamination layer on apaperboard substrate). In one embodiment, the lamination layer could bedisposed on an interior side of the substrate. Alternatively, thecontainer 5 could be formed of any suitable material or suitablecombination of materials. For example, the container 5 could include amolded polymer.

FIGS. 1-3 show one embodiment of the disclosure comprising a container 5with a receptacle 11 that generally has a partial torus shape with aninterior space or cavity 13, an inner edge or perimeter 15, and an outeredge or perimeter 17. For example, as shown in FIGS. 2 and 3, thereceptacle 11 can be generally half a torus so that the cross-section ofthe torus generally forms a semicircle (e.g., as shown partially inphantom in FIG. 3). A centerline C of the container 5 and/or thereceptacle 11 can extend along the base or nadir 19 (e.g., the lowermostpoint of the cross-sectional semicircle) of the receptacle 11 as shownin FIG. 2. In a preferred embodiment, the inner perimeter 15, the outerperimeter 17, and/or the centerline C could be, for example, circular,generally circular, substantially circular, and/or nearly circular. Inan alternative embodiment, the receptacle could have a different shape.For example, either or both of the inner perimeter 15 and the outerperimeter 17 of the receptacle 11 could be an oval, a rectangle, otherpolygons, and/or any other suitable shape. However, in one embodiment,the container with non-circular shapes for the inner perimeter 15, theouter perimeter 17, and/or the centerline C may be less effective atevenly heating food products (e.g., those having a relatively losslessdielectric material, described in more detail below) than a container 5with relatively circular features. In another example, thecross-sectional shape of the receptacle 11 could have a differentarcuate shape (e.g., a ratio of width and depth that is less than one,generally equal to one, or greater than one), could be generallyrectangular (e.g., with sidewalls extending from a bottom wall), orcould have any other suitable shape. Additionally, the centerline C ofthe receptacle 11 could be offset from the nadir 19 and/or the nadir 19could be widened (e.g., so that the receptacle 11 has a flatter bottom).

The container 5 comprises a sidewall 21 (e.g., a bottom wall portionadjacent the nadir 19 and sidewall portions extending upwardly from thebottom wall portion), an inner flange 23 extending at least inwardlyfrom the inner perimeter 15 of the receptacle 11, and an outer flange 25extending at least outwardly from the outer perimeter 17 of thereceptacle 11. Accordingly, the inner perimeter 15 can be disposedadjacent an outer edge 27 of the inner flange 23 with an inner edge 29of the inner flange 23 inwardly spaced from the outer edge 27 and theinner perimeter 15. Similarly, the outer perimeter 17 can be disposedadjacent an inner edge 31 of the outer flange 25 with an outer edge 33of the outer flange 25 outwardly spaced from the inner edge 31 and theouter perimeter 17. Alternatively, the inner flange 23 and/or the outerflange 25 could extend toward the interior space 13 of the receptacle 11from the respective perimeters 15, 17. For example, the inner flange 23could be disposed on the inner perimeter 15 so that the edges 27, 29 arespaced from the inner perimeter 15, and/or the outer flange 25 could bedisposed on the outer perimeter 17 so that the edges 31, 33 are spacedfrom the outer perimeter 17. In one embodiment, the outer flange 25 caninclude handles or tabs 35 where the outer flange is wider than aremainder of the outer flange. Accordingly, the container 5 can begripped at the tabs 35 for lifting and moving the container especiallywhen the contents of the container are hot.

As shown in FIGS. 1-3, the inner perimeter 15, the inner flange 23, theouter perimeter 17, and the outer flange 25 extend around a central axisA of the centerline C. In one embodiment, the inner perimeter 15, theinner flange 23, the outer perimeter 17, and the outer flange 25 can begenerally concentric with the centerline C. The sidewall 21, the innerflange 23, and/or the outer flange 25 could be otherwise shaped,arranged, positioned, and/or configured without departing from thedisclosure. For example, one or both of the flanges 23, 25 could beintegrally formed with the sidewall 21 (e.g., a folded portion of thewall, a rolled rim, and/or another suitable feature) or either of theflanges could be attached to the sidewall 21 and/or an integral flangeportion (e.g., an encapsulated rim, or other suitable feature).

In the illustrated embodiment, the container 5 can include an interioropening adjacent the inner flange 23 and the inner perimeter 15. Theinterior opening and the inner flange 23 generally can form a centralreceiver 37 (FIGS. 1 and 2) for a secondary container 39 (e.g., as shownin FIG. 4 by way of example). In one embodiment, the central receiver 37can cooperate with the inner perimeter 15 and/or an inner portion of thesidewall 21 to function as an inner spacing feature to help retain afood product in the receptacle 11. The (primary) container 5 can supportthe secondary container 39, such as, but not limited to, a bin, tub, orother suitable container for holding a dipping sauce, and/or anothersuitable secondary food item S (FIG. 4) or other item that can accompanyand/or be heated with a primary food item F1 or F2 (e.g., a food item inthe receptacle 11 as shown by example in FIGS. 4 and 5). For example, asshown in FIG. 4, the secondary container 39 can be at least partiallyreceived in the central receiver 37 and at least partially supported bythe inner flange 23 (e.g., a flange and/or another protrusion of thesecondary container can rest on the inner flange 23).

In one embodiment, the secondary container 39 can be engaged with thecentral receiver 37 before, during, and/or after heating. For example,the secondary container 39 can be inserted prior to heating so that theprimary and secondary food items are heated together, and then thecontainer 5 and the secondary container can act as a serving tray forthe food items F1, S after heating. Alternatively, the secondarycontainer 39 could be inserted after heating of the primary food item F1in the receptacle 11, and the container 5 can support the secondarycontainer 39 and act as a serving tray for the primary and secondaryfood items F1, S. The central receiver 37 and/or the secondary container39 could be otherwise shaped, arranged, positioned, and/or configuredwithout departing from the disclosure. For example, the secondarycontainer 39 could be integrally formed with the inner flange 23 and/oranother portion of the container 5. Additionally, at least the inneredge 29 of the inner flange 23 could be a different shape than thegeneral shape of the container 5 for accommodating a secondary container39 with a different shape. For example, the secondary container 39 couldhave a generally oval or rectangular shape, and the flange 23 can beshaped accordingly for receiving the secondary container 39.Alternatively, the inner flange 23 could have a different shape than thesecondary container 39.

In one embodiment, as shown in FIG. 2 the inner perimeter 15 can have adiameter of D1, the outer perimeter 17 can have a diameter of D2, andthe outer perimeter 17 generally can be spaced apart from the innerperimeter 15 by a distance D3. As shown in FIG. 3, the centerline C atthe nadir 19 can have a diameter of D4, and the semicircularcross-section of the receptacle 11 can have a diameter D5. As shown inFIG. 3, the receptacle 11 can have a depth of distance D6. In theillustrated embodiment, the depth of the receptacle is generally theradius of the semicircular cross-section of the receptacle, and thedistance D6 is generally half the diameter D5. Also in the illustratedembodiment, the distance D3 between the perimeters 15, 17 can begenerally equal to the diameter D1 of the inner perimeter 15, and thediameter D4 of the centerline C at the nadir 19 can be generally twicethe diameter D1 of the inner perimeter 15. Additionally, the diameter D2of the outer perimeter 17 can be generally three times the diameter D1of the inner perimeter 15. In one embodiment, the distance D3 can be themaximum width of the cavity 13 extending radially from the innerperimeter 15 to the outer perimeter 17 since the cross-section of thereceptacle 11 is generally semicircular (FIG. 3). The dimensions of thecontainer 5 could be otherwise configured without departing from thedisclosure.

In the illustrated embodiment, the container 5 can be geometricallydimensioned for improved simultaneous heating of two or more differentfood items with different relative responses to microwave energy withoutrequiring a microwave energy interactive material (e.g., a susceptor,shield, or other active material) incorporated into or used with thecontainer 5. For example, a first or primary food item F1 or F2 (e.g.,one or more pellets, chips, Nibbits, and/or other suitable solid and/orliquid food items) can be disposed in the interior space 13 of thereceptacle 11, and a secondary food item S (e.g., one or more dippingsauces, toppings, ingredients to be mixed in with the primary food item,and/or any other suitable solid and/or liquid food items) can bedisposed in a secondary container 39 received in the central receiver 37so that the secondary food item 39 is generally centered in thecontainer 5.

In one embodiment, the primary food item generally can comprise adielectric material that is relatively lossless as compared to thesecondary food item (e.g., the secondary food item can comprise arelatively lossy dielectric material). For example, the secondary fooditem can include relatively more water, salt, and/or fat than theprimary food item. In one embodiment, a relatively lossless dielectricmaterial generally will not disperse energy as heat as readily and/or aseasily as a relatively lossy dielectric material. Accordingly, a fooditem comprising a relatively lossy dielectric material generally willheat up faster/more easily when exposed to microwave energy (e.g., in amicrowave oven) than a food comprising relatively lossless dielectricmaterial when heated under similar conditions (e.g., in electromagneticfields having similar amplitudes). As a result, the secondary food itemS in the secondary container 39 received in the central receiver 37generally will heat more readily/easily when exposed to microwave energythan the primary food item F1 in the receptacle 11. However, asdescribed in more detail below, the geometry of the container 5 can beconfigured to cooperate with the distribution of the electromagneticfield produced in the microwave oven so that the primary food item F1 isexposed to higher amplitude of the electromagnetic field than thesecondary food item S.

In the illustrated embodiment, the dielectric property of a material(e.g., food) includes its electric permittivity and/or its magneticpermeability. Food products often can be non-magnetic dielectricmaterials so that the conversion of the electric field component ofmicrowave energy into heat can be dependent on the complex permittivityof the material. The complex permittivity includes a dielectric constant(e.g., the electric charge or energy storage capability of a materialrelative to free space) and a dielectric loss factor (e.g., the abilityof a material to absorb energy from an electric field and subsequentlydissipate the energy into heat relative to free space). The heatdissipation can be due to dipole relaxation (i.e., for polar molecules,such as water molecules) and/or ionic absorption (i.e., for dissolvedions, such as salt in a food material). Accordingly, in one exemplaryembodiment, a first food product with little or no polar moleculesand/or dissolved ions may have worse heat dissipation (e.g., may be arelatively lossless dielectric material) compared with a second foodproduct with more polar molecules and/or dissolved ions. Accordingly,the second food product may have relatively better heat dissipation(e.g., may be a relatively lossy dielectric material).

In the illustrated embodiment, the geometric dimensions of the container5 can be configured so that the primary food item, comprising arelatively lossless dielectric material, can be heated along with asecondary food item comprising a relatively lossy dielectric material.For example, the diameter D4 of the centerline C at the nadir 19 can begenerally equal to the wavelength (e.g., the average wavelength) of themicrowaves (e.g., the electromagnetic field) in the microwave oven, andthe curved sidewall 21 of the receptacle 11 can help generally retainthe primary food F1 item in an area proximate to the centerline C andthe nadir 19. In one embodiment, the diameter D1 and the distance D3generally can be equal to half the wavelength of the microwaves, and,accordingly, the secondary food item can be confined to the centralportion of the container 5 in a diameter that is less than half thewavelength of the microwaves and that is less than a quarter of thewavelength from the central axis A of the centerline C.

In one embodiment, this configuration of the dimensions of the container5 can help retain the primary food item (e.g., the relatively losslessdielectric material) in an area that generally will be exposed to moremicrowave energy (e.g., in a circle with a diameter of one wavelength)than the central portion of the container 5 where the secondary fooditem can be contained (e.g., within a quarter of a wavelength from thecentral axis A of the centerline C) since the microwave energy or theelectric field due to the microwaves tends to be more intense (e.g.,have a higher amplitude) in the area that is generally half themicrowave wavelength from the central axis A of the centerline C. Sincethe cross-section of the receptacle 11 is generally semicircular, thediameter D5 is generally equal to the distance D3 (at half thewavelength) and the depth D6 is generally equal to half the diameter D5(at a quarter of the wavelength). Accordingly, these dimensions D5, D6can further help retain the primary food item in the area of highermicrowave energy during heating. Further, due to the generally circularconfiguration of the receptacle 11 (with the generally half-torusshape), the microwaves generally are evenly distributed andgeometrically reflected in the location of the lossless dielectricmaterial (the primary food F1 item in the receptacle 11). Any of thedimensions of the container 5 could be alternatively configured withrespect to the wavelength of the microwaves and/or the food items couldbe alternatively positioned without departing from the scope of thedisclosure.

In the illustrated embodiment, during heating, the primary food item F1in the receptacle 11 generally will be exposed to an electric field witha higher amplitude than the electric field at the central portion of thecontainer. Since the relatively lossless dielectric material of theprimary food item F1 experiences a higher amplitude electric field thanthe secondary food item S in the central portion of the container 5, theprimary food item F 1 can heat up at a rate that is similar to oridentical to the rate of heating of the secondary food item S with therelatively lossy dielectric material. Stated another way, the relativelylossy dielectric material would typically heat up much faster than therelatively lossless dielectric material; however, the positioning of theprimary and secondary food items F1, S results in the relatively lossydielectric material receiving a lower amplitude electric field than therelatively lossless dielectric material, and the food items can heat upat generally similar rates.

Accordingly, the container 5 can help generally slow the heating of therelatively lossy dielectric material of the secondary food item S and/orgenerally speed up the heating of the relatively lossless dielectricmaterial of the primary food item F1 without the use of coatings,laminated layers, or other features with microwave energy interactivematerials that can at least partially shield the secondary food item Sand/or generate heat near the primary food item F1, for example. Inother words, the container 5 uses natural wave transmission andreflection at the interface of two different dielectric media (e.g., atan interface between air and the surface of the food item) rather thanactive elements. Such active elements (e.g., microwave energyinteractive materials) can add cost and/or weight to the container, forexample. In an alternative embodiment, an active element can be used inconjunction with the geometric configuration of the container 5.

The active or microwave energy interactive elements can includematerials such as is common in MicroRite® containers available fromGraphic Packaging International of Marietta, Ga. A microwave interactionlayer can be commonly referred to as, or can have as one of itscomponents, a foil, a microwave shield, or any other term or componentthat refers to a layer of material suitable for shielding microwaveenergy and/or causing heating in a microwave oven. Alternatively, themicrowave interaction layer can be any suitable material that islaminated onto a substrate, which can be in the form of paperboard,cardboard, polymer, or any other suitable material. The microwaveinteraction layer can be other suitable microwave interactive materialsset forth below, or any other suitable material.

In one exemplary embodiment, the container 5 can be dimensioned for usein a microwave oven that generates microwaves at a wavelength (e.g., anaverage wavelength) of approximately 12.2 centimeters (cm), whichcorrelates to a microwave frequency of approximately 2.45 gigahertz(GHz). Accordingly, the diameter D4 of the centerline C is approximately122 millimeters (mm). The diameter D1 of the inner perimeter 15, thedistance D3 between the perimeters 15, 17, and the diameter D5 of thecross-section of the receptacle 11 can be approximately 61 mm or half awavelength. Additionally, the depth D6 of the container 5 can beapproximately 30 mm or a quarter of a wavelength. Alternatively, thedimensions could be configured for microwaves or other suitableelectromagnetic radiation having any suitable wavelength or frequency,such as wavelengths that are smaller than 12.2 cm or larger than 12.2cm. For example, an alternative microwave oven could generate microwavesat a wavelength of approximately 32.8 cm, which correlates to amicrowave frequency of approximately 915 megahertz (MHz), and thediameters D4, D1 could be approximately 328 mm and 164 mm, respectively.Other microwave, radio wave, or other electromagnetic wave frequenciesthat could be used include frequencies of approximately 433.92 MHz,approximately 896 MHz, 2375 MHz, and/or any suitable frequency in therange of approximately 13 MHz to approximately 24 GHz, for example.

Any of the dimensions noted above could be larger or smaller than notedor could be inside or outside the listed ranges without departing formthe scope of the disclosure. All of the dimensional informationpresented herein is intended to be illustrative of certain aspects ofthe disclosure and is not intended to limit the scope of the disclosure,as various other embodiments of the disclosure could include dimensionsthat are greater than or less than the dimensions included herein.

As shown in FIG. 4, the secondary container 39 is received in the innerreceptacle 37 of the container 5 so that the flange of the secondarycontainer 39 rests on the inner flange 23 of the container 5. Thesecondary container 39 alternatively could be integral with or attachedto the container 5. In the illustrated embodiment, the secondarycontainer 39 can be generally coaxial/concentric with the receptacle 11.As shown in FIG. 4, the receptacle 11 and/or the secondary container 39can be at least partially covered by a cover 41 (e.g., a sheet ofplastic or other suitable material and/or any other suitable cover orlid). The primary food item F1 is disposed in the interior space 13 ofthe receptacle 11. Additionally, the secondary food item S is disposedin an interior space or cavity 43 of the secondary container 39. In oneembodiment, the secondary container 39 could have a separate and/oradditional lid or cover that is, for example, under and/or spaced fromthe cover 41. In an exemplary embodiment, the secondary food item S cancomprise a relatively lossy dielectric material as compared to theprimary food item F1, which is a relatively lossless dielectricmaterial. The container 5 including the receptacle 11, the secondarycontainer 39, the cover 41, and/or the food item F1 could be otherwiseshaped, arranged, positioned, and/or configured without departing fromthe disclosure.

As shown in FIG. 4, the primary food item F1 can be a chip, such asSakata Mini (e.g., rice chips), disposed in the receptacle 11. Theprimary food item F1 generally can be disposed in a ring with a diameterthat is generally equal to the wavelength of the microwaves emitted by amicrowave oven (e.g., in proximity to the centerline C and the nadir 19of the receptacle 11). Additionally, the secondary food item S (e.g., adipping sauce) can be contained in the secondary container 39, which isreceived in the central receiver 37. The entire package can be enclosedby a cover 41.

Alternatively, as shown in FIG. 5, a different primary food item F2,such as Nibbits (e.g., a puffed pellet), can be retained in thereceptacle 11. As shown in FIG. 5, the secondary food item S could beomitted. Alternatively, any suitable secondary food item and secondarycontainer could be received in the central receiver 37.

In one example, the primary food item F1 (e.g., Sakata Mini rice chips)is disposed generally along a centerline with a diameter that isapproximately equal to the wavelength of the microwave energy producedby a particular microwave oven and is heated in that microwave oven. Thesecondary food item was omitted in this example. After heating theprimary food item F1 in the microwave oven (e.g., for approximately 30seconds), the primary food item F1 becomes puffed (e.g., expands) witheven cooking and no observable burning.

In another example, the primary food item F2 (e.g., Nibbits) is disposedgenerally along a centerline with a diameter that is approximately equalto the wavelength of the microwave energy produced by a particularmicrowave oven and is heated in that microwave oven. After heating theprimary food item F2 for approximately 30 seconds, the primary food itemF2 generally becomes puffed and heated with a minimal amount of burningobserved.

FIGS. 6-8 are views of a container 105 according to a second embodimentof the disclosure. The second embodiment is generally similar to thefirst embodiment, except for variations noted and variations that willbe apparent to one of ordinary skill in the art. Accordingly, similar oridentical features of the embodiments have been given like or similarreference numbers. As shown in FIG. 6, the container 105 includes areceptacle 111 and an inner spacing feature 137. In the illustratedembodiment, the inner spacing feature 137 includes a top panel 123extending across the inner spacing feature 137 instead of the flange 23and inner receptacle 37 of the first embodiment. As shown in FIG. 6, thetop panel 123 can extend inwardly from the inner perimeter 115 of thereceptacle 111. The inner spacing feature 137 can include the innerperimeter 115 and an inner portion of the sidewall 121 to help retainthe food product in the receptacle 111, outwardly of the interior of thecontainer 105. The receptacle 111 and/or the inner spacing feature 137could be otherwise shaped, arranged, positioned, and/or configuredwithout departing from the disclosure.

As shown in FIGS. 7 and 8, in one embodiment, similarly to the firstembodiment, the diameter D4 of the centerline C at the nadir 119 of thecontainer 105 is generally equal to the wavelength (e.g., the averagewavelength) of the microwave energy produced in the microwave oven inwhich the container 105 is to be used. Additionally, similarly to thefirst embodiment, the diameter D5 of the outer wall of the receptacle111 is generally equal to half of the wavelength (e.g., half the averagewavelength) of the microwaves in the microwave oven, and the depth D6 ofthe receptacle 111 is generally equal to a quarter of the wavelength(e.g., a quarter the average wavelength) of the microwave energy. Incontrast to the first embodiment, the diameter D7 of the top panel 123of the inner spacing feature 137 generally is larger than the distanceD8. For example, in one embodiment wherein the average wavelength of themicrowaves is approximately 122 mm, the diameter D7 could beapproximately 69.46 mm and the distance D8 could be approximately 56.48mm. In an alternative embodiment, the diameter D7 and the distance D8could be generally equal, or the distance D8 could be larger than thediameter D7.

As shown in FIG. 8, the height D9 of the inner spacing feature 137 isapproximately or generally greater than half the depth D6 of thereceptacle 111. For example, in one embodiment wherein the averagewavelength of the microwaves is approximately 122 mm, the depth D6 ofthe receptacle 111 is approximately 30 mm and the height D9 of the innerspacing feature 137 is approximately 15.5 mm. In an alternativeembodiment, the height D9 could be any suitable height (e.g., less thanhalf the depth D6, generally equal to the depth D6, greater than thedepth D6, etc.).

In use, the container 105 can help a food item comprising a generallylossless dielectric material to cook evenly when exposed to microwaveenergy (e.g., in a microwave oven). For example, the curved wall 121 ofthe receptacle 111 can cooperate with the inner spacing feature 137 tohelp retain the food item placed in the cavity 113 in proximity to thecenterline C of the receptacle 111. The food item generally is retainedin a generally circular area having a diameter that is approximatelyequal to the average wavelength of the microwave energy (e.g., thediameter D4 of the centerline C is configured to be approximately equalto the average wavelength). Accordingly, the food item in the receptacle111 (e.g., in an area that is less than a quarter of a wavelength of themicrowave energy from the centerline C) will be exposed to a generallyconsistent heating energy (e.g., a generally consistent electromagneticfield intensity) throughout the receptacle 111 whereas food items spacedfarther inwardly or outwardly from the centerline C may be exposed to adifferent intensity (e.g., lower) of microwave energy. Retaining thefood item in proximity to the centerline C promotes even heating of thefood item since generally lossless dielectric material generally willnot disperse energy as heat as readily and/or as easily (e.g., to areasexposed to less microwave energy) as a relatively lossy dielectricmaterial. Retaining the food item having relatively lossless dielectricmaterial in proximity to the centerline C can help reduce overheatingand/or under-heating of portions of the food item since most or all ofthe food item is exposed to substantially the same or nearly the samemicrowave energy.

FIGS. 9-11 are views of a container 205 according to a third embodimentof the disclosure. The third embodiment is generally similar to thefirst and second embodiments, except for variations noted and variationsthat will be apparent to one of ordinary skill in the art. Accordingly,similar or identical features of the embodiments have been given like orsimilar reference numbers. As shown in FIG. 9, the container 205includes a support element 251 supporting four receptacles 211. In oneembodiment, the support element 251 can be formed from one or morematerials, such as, but not limited to, paperboard, cardboard, paper,polymeric sheet(s), molded polymer(s), and/or laminates and/or othercombinations thereof. As shown in FIGS. 9 and 10, the support element251 includes a top panel 253 supported by two side panels 255 and a basepanel 257. The top panel 253 has an opening 259 for each of thereceptacles 211. In the illustrated embodiment, the container 205includes four receptacles 211 and four openings 259. Alternatively, thecontainer 205 could include any suitable number of receptacles 211 andopenings 259. As shown in FIG. 10, the openings 259 generally cancorrespond in shape to the respective sidewalls 221 of the respectivereceptacles. The receptacles 211 have respective cavities 213 and can beindividually removed from the support element 251 to function as servingdishes for respective users.

As shown in FIGS. 9 and 11, the cavity 213 of each receptacle 211 is atleast partially defined by a bottom wall 219 and a sidewall 221extending upwardly from the bottom wall 219. In the illustratedembodiment, the bottom wall 219 can form a base for setting thereceptacle 211 on a table, for example, when functioning as a servingdish. Alternatively, the sidewall 221 and the bottom wall 219 can becurved to form a rounded bottom similarly to the sidewalls 21, 121 ofthe first and second embodiments. As shown in FIG. 11, the sidewall 221includes an inner curved portion 245, an outer curved portion 247, andtwo oblique portions 249 extending between the inner curved portion 245and the outer curved portion 247. In the illustrated embodiment, theinner curved portion 245 is convex relative to the cavity 213 and theouter curved portion 247 is concave relative to the cavity 213. Theinner curved portion 245 and the outer curved portion 247 of thesidewall 221 of the receptacles 211 can cooperate to help retain a fooditem in the cavities 213 in a generally circular area around a centralaxis of the container 205. For example, in one embodiment, the innercurved portions 245 of the sidewalls 221 of the receptacles 211 cancooperate to generally form an inner circle and the outer curvedportions 247 of the sidewalls 221 can cooperate to generally form anouter circle, wherein the difference between the diameters of innercircle and the outer circle can be generally analogous to the centerlineC of the second embodiment (FIG. 7). Accordingly, in one embodiment, thecavities 213 of the receptacles can be arranged to retain a food item(e.g., a food item comprising a relatively lossless dielectric materialor any other suitable food item) in a generally circular area having anaverage diameter that is approximately equal to the average wavelengthof the microwaves produced in a microwave oven similarly to thecontainer 105 in the second embodiment. Alternatively, the centerlinecould be spaced any suitable distance from the inner circle and/or theouter circle.

As shown in FIG. 11, each of the receptacles 211 can have an innerflange 223 extending inwardly from a top edge of the inner curvedportion 245 of the sidewall 221, an outer flange 225 extending outwardlyfrom a top edge of the outer curved portion 247 of the sidewall 221, andtwo intermediate flanges 243 extending from the respective obliqueportions 249 of the sidewall 221. The flanges 223, 225, 243 cancooperate to form a continuous peripheral flange for each receptacle221, and the flanges can rest on the top panel 253 of the supportelement 251 adjacent the respective opening 259. Accordingly, the toppanel 253 can help support the receptacles 211 at the flanges 223, 225,243 and retain the receptacles 211 in the illustrated position (FIG. 9).The bottom walls 219 of the receptacles 211 can rest on the base panel257 of the support element 251 in one embodiment. The outer flange 225of each receptacle 211 can include an outer tab 235 and the inner flange223 of the respective receptacles 211 can form an inner tab.Accordingly, each of the receptacles 211 can be lifted out of thesupport element 251 and/or held at the outer tab 235 and/or the innerflange 223.

The container 205, including the support element 251 and/or any or allof the receptacles 211, could be otherwise shaped, arranged, positioned,and/or configured without departing from the disclosure.

Any of the features of the various embodiments of the disclosure can becombined with, replaced by, or otherwise configured with other featuresof other embodiments of the disclosure without departing from the scopeof this disclosure.

Optionally, one or more portions of the blank or other constructsdescribed herein or contemplated hereby may be coated with varnish,clay, or other materials, either alone or in combination. The coatingmay then be printed over with product advertising or other informationor images. The blanks or other constructs also may be selectively coatedand/or printed so that less than the entire surface area of the blank orsubstantially the entire surface area of the blank may be coated and/orprinted.

Further, the containers disclosed herein may cooperate with a lid (notshown) for heating and/or cooking a food product that is held in thecontainer without departing from the disclosure.

In an alternative embodiment, any of the blanks, containers, or otherconstructs of this disclosure may optionally include one or morefeatures that alter the effect of microwave energy during the heating orcooking of a food item that is associated with the tray or otherconstruct. For example, the blank, tray, container, or other constructmay be formed at least partially from one or more microwave energyinteractive elements (hereinafter sometimes referred to as “microwaveinteractive elements”) that promote heating, browning and/or crisping ofa particular area of the food item, shield a particular area of the fooditem from microwave energy to prevent overcooking thereof, or transmitmicrowave energy towards or away from a particular area of the fooditem. Each microwave interactive element comprises one or more microwaveenergy interactive materials or segments arranged in a particularconfiguration to absorb microwave energy, transmit microwave energy,reflect microwave energy, or direct microwave energy, as needed ordesired for a particular construct and food item.

In the case of a susceptor or shield, the microwave energy interactivematerial may comprise an electroconductive or semiconductive material,for example, a vacuum deposited metal or metal alloy, or a metallic ink,an organic ink, an inorganic ink, a metallic paste, an organic paste, aninorganic paste, or any combination thereof Examples of metals and metalalloys that may be suitable include, but are not limited to, aluminum,chromium, copper, inconel alloys (nickel-chromium-molybdenum alloy withniobium), iron, magnesium, nickel, stainless steel, tin, titanium,tungsten, and any combination or alloy thereof

Alternatively, the microwave energy interactive material may comprise ametal oxide, for example, oxides of aluminum, iron, and tin, optionallyused in conjunction with an electrically conductive material. Anothermetal oxide that may be suitable is indium tin oxide (ITO). ITO has amore uniform crystal structure and, therefore, is clear at most coatingthicknesses.

Alternatively still, the microwave energy interactive material maycomprise a suitable electroconductive, semiconductive, or non-conductiveartificial dielectric or ferroelectric. Artificial dielectrics compriseconductive, subdivided material in a polymeric or other suitable matrixor binder, and may include flakes of an electroconductive metal, forexample, aluminum.

In other embodiments, the microwave energy interactive material may becarbon-based, for example, as disclosed in U.S. Pat. Nos. 4,943,456,5,002,826, 5,118,747, and 5,410,135.

In still other embodiments, the microwave energy interactive materialmay interact with the magnetic portion of the electromagnetic energy inthe microwave oven. Correctly chosen materials of this type canself-limit based on the loss of interaction when the Curie temperatureof the material is reached. An example of such an interactive coating isdescribed in U.S. Pat. No. 4,283,427.

The use of other microwave energy interactive elements is alsocontemplated. In one example, the microwave energy interactive elementmay comprise a foil or high optical density evaporated material having athickness sufficient to reflect a substantial portion of impingingmicrowave energy. Such elements typically are formed from a conductive,reflective metal or metal alloy, for example, aluminum, copper, orstainless steel, in the form of a solid “patch” generally having athickness of from about 0.000285 inches to about 0.005 inches, forexample, from about 0.0003 inches to about 0.003 inches. Other suchelements may have a thickness of from about 0.00035 inches to about0.002 inches, for example, 0.0016 inches.

In some cases, microwave energy reflecting (or reflective) elements maybe used as shielding elements where the food item is prone to scorchingor drying out during heating. In other cases, smaller microwave energyreflecting elements may be used to diffuse or lessen the intensity ofmicrowave energy. One example of a material utilizing such microwaveenergy reflecting elements is commercially available from GraphicPackaging International, Inc. (Marietta, Ga.) under the trade nameMicroRite® packaging material. In other examples, a plurality ofmicrowave energy reflecting elements may be arranged to form a microwaveenergy distributing element to direct microwave energy to specific areasof the food item. If desired, the loops may be of a length that causesmicrowave energy to resonate, thereby enhancing the distribution effect.Microwave energy distributing elements are described in U.S. Pat. Nos.6,204,492, 6,433,322, 6,552,315, and 6,677,563, each of which isincorporated by reference in its entirety.

If desired, any of the numerous microwave energy interactive elementsdescribed herein or contemplated hereby may be substantially continuous,that is, without substantial breaks or interruptions, or may bediscontinuous, for example, by including one or more breaks or aperturesthat transmit microwave energy. The breaks or apertures may extendthrough the entire structure, or only through one or more layers. Thenumber, shape, size, and positioning of such breaks or apertures mayvary for a particular application depending on the type of constructbeing formed, the food item to be heated therein or thereon, the desireddegree of heating, browning, and/or crisping, whether direct exposure tomicrowave energy is needed or desired to attain uniform heating of thefood item, the need for regulating the change in temperature of the fooditem through direct heating, and whether and to what extent there is aneed for venting.

By way of illustration, a microwave energy interactive element mayinclude one or more transparent areas to effect dielectric heating ofthe food item. However, where the microwave energy interactive elementcomprises a susceptor, such apertures decrease the total microwaveenergy interactive area, and therefore, decrease the amount of microwaveenergy interactive material available for heating, browning, and/orcrisping the surface of the food item. Thus, the relative amounts ofmicrowave energy interactive areas and microwave energy transparentareas may be balanced to attain the desired overall heatingcharacteristics for the particular food item.

As another example, one or more portions of a susceptor may be designedto be microwave energy inactive to ensure that the microwave energy isfocused efficiently on the areas to be heated, browned, and/or crisped,rather than being lost to portions of the food item not intended to bebrowned and/or crisped or to the heating environment. Additionally oralternatively, it may be beneficial to create one or morediscontinuities or inactive regions to prevent overheating or charringof the food item and/or the construct including the susceptor.

As still another example, a susceptor may incorporate one or more “fuse”elements that limit the propagation of cracks in the susceptor, andthereby control overheating, in areas of the susceptor where heattransfer to the food is low and the susceptor might tend to become toohot. The size and shape of the fuses may be varied as needed. Examplesof susceptors including such fuses are provided, for example, in U.S.Pat. No. 5,412,187, U.S. Pat. No. 5,530,231, U.S. Patent ApplicationPublication No. US 2008/0035634A1, published Feb. 14, 2008, and PCTApplication Publication No. WO 2007/127371, published Nov. 8, 2007, eachof which is incorporated by reference herein in its entirety.

The blanks according to the present invention can be, for example,formed from coated paperboard and similar materials. For example, theinterior and/or exterior sides of the blanks can be coated with a claycoating. The clay coating may then be printed over with product,advertising, price coding, and other information or images. The blanksmay then be coated with a varnish to protect any information printed onthe blanks. The blanks may also be coated with, for example, a moisturebarrier layer, on either or both sides of the blanks.

In accordance with the exemplary embodiments, the blanks and/or otherconstructs may be constructed of paperboard of a caliper such that it isheavier and more rigid than ordinary paper. The blanks can also beconstructed of other materials, such as cardboard, hard paper, or anyother material having properties suitable for enabling the cartonpackage to function at least generally as described above.

The foregoing description illustrates and describes various embodimentsof the present disclosure. As various changes could be made in the aboveconstruction without departing from the scope of the disclosure, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense. Furthermore, the scope of the present disclosurecovers various modifications, combinations, and alterations, etc., ofthe above-described embodiments. Additionally, the disclosure shows anddescribes only selected embodiments, but various other combinations,modifications, and environments are contemplated and are within thescope of the inventive concept as expressed herein, commensurate withthe above teachings, and/or within the skill or knowledge of therelevant art. Furthermore, certain features and characteristics of eachembodiment may be selectively interchanged and applied to otherillustrated and non-illustrated embodiments without departing from thescope of the disclosure.

What is claimed is:
 1. A container for heating a food product withmicrowave energy comprising a wavelength, the container comprising: agenerally circular centerline having an axis; a receptacle comprising asidewall extending at least partially around a cavity, at least aportion of the cavity extending along at least a portion of thecenterline; and a support element comprising a top panel having at leastone opening at least partially receiving the receptacle; the sidewallcomprising an inner edge and an outer edge each being spaced apart fromthe axis of the centerline for at least partially retaining the foodproduct in the cavity in proximity to the centerline.
 2. The containerof claim 1, wherein the inner edge is generally circular and isgenerally concentric with the centerline.
 3. The container of claim 2,wherein the centerline has a first diameter that is generally equal tothe wavelength of the microwave energy, and the inner edge has a seconddiameter that is generally equal to at least half the wavelength of themicrowave energy.
 4. The container of claim 3, wherein the outer edgeextends around an outer perimeter of the receptacle and is spaced apartfrom the inner edge by at least half the wavelength of the microwaveenergy.
 5. The container of claim 1, wherein the inner edge extendsalong an inner perimeter of the receptacle and at least partially aroundthe axis of the centerline.
 6. The container of claim 5, wherein theouter edge extends along an outer perimeter of the receptacle and atleast partially around the axis of the centerline.
 7. The container ofclaim 5, further comprising an inner receptacle disposed within theinner perimeter.
 8. The container of claim 7, wherein the centerline hasa diameter that is generally equal to the wavelength of the microwaveenergy, and the inner receptacle is generally confined to within aquarter of the wavelength from the axis of the centerline.
 9. Thecontainer of claim 8, wherein the food product comprises a primary fooditem for being disposed in the cavity of the receptacle and a secondaryfood item for being disposed in a secondary container that is for beingreceived in the inner receptacle, and the primary food item is for beingexposed to relatively higher microwave energy in the cavity of thereceptacle than the secondary food item in the inner receptacle.
 10. Thecontainer of claim 9, wherein the primary food item comprises agenerally lossless dielectric material and the secondary food itemcomprises a dielectric material that is relatively lossy with respect tothe generally lossless dielectric material.
 11. The container of claim7, further comprising an inner flange extending inwardly from the inneredge, the inner flange at least partially defining the inner receptacle.12. The container of claim 5, further comprising an inner spacingfeature at least partially defined by the inner edge.
 13. The containerof claim 1, further comprising an inner flange extending from the inneredge and an outer flange extending from the outer edge.
 14. Thecontainer of claim 13, wherein the inner flange extends along an innerperimeter of the receptacle and the outer flange extends along an outerperimeter of the receptacle.
 15. The container of claim 1, wherein: thereceptacle is a first receptacle, the sidewall is a first sidewall, andthe cavity is a first cavity; the container further comprises at least asecond receptacle comprising a second sidewall extending at leastpartially around a second cavity, at least a portion of the secondcavity extending along at least a portion of the centerline.
 16. Thecontainer of claim 15, wherein each of the first sidewall and the secondside wall comprises an inner portion, an outer portion spaced apart fromthe inner portion, and an oblique portion extending from the respectiveinner portion to the respective outer portion.
 17. The container ofclaim 16, wherein the oblique portion of the first sidewall is disposedproximate to the oblique portion of the second sidewall.
 18. Thecontainer of claim 16, wherein the centerline has a diameter that isgenerally equal to the wavelength of the microwave energy, and, for eachof the first sidewall and the second sidewall, the inner portion isspaced apart from the axis of the centerline by at least a quarter ofthe wavelength from the axis of the centerline.
 19. The container ofclaim 18, wherein, for each of the first sidewall and the secondsidewall, the outer portion is spaced apart from the inner portion bygenerally less than half the wavelength of the microwave energy.
 20. Thecontainer of claim 15, wherein the at least one opening comprises afirst opening at least partially receiving the first receptacle and asecond opening at least partially receiving the second receptacle. 21.The container of claim 20, wherein the first opening and the secondopening of the support element at least partially retain the respectivefirst receptacle and second receptacle so that each of the first cavityand the second cavity is at least partially disposed along at least aportion of the centerline.
 22. The container of claim 20, wherein thefirst receptacle comprises a first flange extending from the firstsidewall and the second receptacle comprises a second flange extendingfrom the second sidewall, and each of the first flange and the secondflange engages the top panel of the support element to at leastpartially support the respective first receptacle and second receptacle.23. The container of claim 1, wherein the support element comprises twoside panels foldably connected to the top panel and a base panelfoldably connected to the two side panels.
 24. The container of claim 1,wherein the support element comprises paperboard.
 25. The container ofclaim 1, wherein the wavelength of the microwave energy is an averagewavelength of the microwave energy, and the centerline has a diameterthat is generally equal to the average wavelength of the microwaveenergy.
 26. The container of claim 1, wherein the wavelength of themicrowave energy is an average wavelength of the microwave energy, andthe cavity comprises a maximum width extending radially from the inneredge to the outer edge, the maximum width being generally equal to orless than half the average wavelength of the microwave energy.
 27. Thecontainer of claim 26, wherein the food product comprises a generallylossless dielectric material.
 28. A method of heating a food product,comprising: obtaining a container comprising a generally circularcenterline having an axis, a receptacle comprising a sidewall extendingat least partially around a cavity, a support element comprising a toppanel having at least one opening, at least a portion of the cavityextending along at least a portion of the centerline, the sidewallcomprising an inner edge and an outer edge each being spaced apart fromthe axis of the centerline for at least partially retaining the foodproduct in the cavity in proximity to the centerline; positioning atleast a portion of the food product in the cavity; positioning thereceptacle in the at least one opening so the receptacle is at leastpartially received in the opening; and exposing the container and thefood product to microwave energy comprising a wavelength.
 29. The methodof claim 28, wherein the inner edge is generally circular and isgenerally concentric with the centerline.
 30. The method of claim 29,wherein the centerline has a first diameter that is generally equal tothe wavelength of the microwave energy, and the inner edge has a seconddiameter that is generally equal to at least half the wavelength of themicrowave energy.
 31. The method of claim 30, wherein the outer edgeextends around an outer perimeter of the receptacle and is spaced apartfrom the inner edge by at least half the wavelength of the microwaveenergy.
 32. The method of claim 28, wherein: the container furthercomprises an inner receptacle disposed within the inner perimeter,wherein: the food product comprises a primary food item and a secondaryfood item, the positioning at least a portion of the food productcomprises positioning the first food item in the cavity; and the methodfurther comprises disposing the secondary food item in a secondarycontainer and positioning the secondary container to be at leastpartially received in the inner receptacle.
 33. The method of claim 32,wherein the centerline has a diameter that is generally equal to thewavelength of the microwave energy, and the inner receptacle isgenerally confined to within a quarter of the wavelength from the axisof the centerline, and the exposing the container and the food productto the microwave energy comprises producing the microwave energy havingat least the wavelength so that the primary food item generally isexposed to a relatively higher intensity of the microwave energy in thecavity of the receptacle than the secondary food item is generallyexposed to in the inner receptacle.
 34. The method of claim 33, whereinthe primary food item comprises a generally lossless dielectric materialand the secondary food item comprises a dielectric material that isrelatively lossy with respect to the generally lossless dielectricmaterial.
 35. The method of claim 28, wherein: the receptacle is a firstreceptacle, the sidewall is a first sidewall, and the cavity is a firstcavity; the container further comprises at least a second receptaclecomprising a second sidewall extending at least partially around asecond cavity, at least a portion of the second cavity extending alongat least a portion of the centerline; and the positioning at least aportion of the food product further comprises positioning at least aportion of the food product in the second cavity.
 36. The method ofclaim 35, wherein the at least one opening comprises a first opening atleast partially receiving the first receptacle and a second opening atleast partially receiving the second receptacle, the method furthercomprising at least partially removing at least one of the firstreceptacle and the second receptacle from the support element after theexposing the container and the food product to the microwave energy. 37.The method of claim 28, wherein the wavelength of the microwave energyis an average wavelength of the microwave energy, and the centerline hasa diameter that is generally equal to the average wavelength of themicrowave energy.
 38. The method of claim 37, wherein the food productcomprises a generally lossless dielectric material.